Brush lifter



May 31, 1949. J. A. JOHNSON BRUSH LIFTER 2 Sheets-Sheet 1 Filed March 29, 1947 J- A. JOHNSON BRUSH LIFTER I 2 Sheets-Sheet 2 Filed March 29, 1947 s a? w\ :1 vi. N w w w 1 iv F. mg? g mum/me J05. 1 2 Jay/v0 0N Patented May 31, 1949 UNITED STATES PATENT OFFICE 6 Claims.

This invention relates to devices for use as an aid in the repairing and overhauling of electric generators of the type of those used in connection with automobile engines for supplying electric current to the ignition system and for recharging the storage battery; it being the principal object of the invention to provide a practical and relatively simple device that may be applied to a generator and used for lifting the commutator brushes so that the commutator portion of the generator as attached to the rotor or armature may be moved into and from normal operating position without interference by the rushes.

Explanatory to the invention it will be stated that when a generator is overhauled or repaired, it is customary to withdraw the armature from the generator housing. The commutator brushes which are carried by the generator housing and are normally yieldingly pressed into contact with the commutator bars will, upon removal of the armature, drop down and interfere with the subsequent reassembly of parts.

Various ways of overcoming this difficulty have been employed, for example, by extending wires beneath the brushes and pulling them up, or by reaching into the restricted brush space with a tool such as a screw driver. But regardless of the means used, it is a difiicult and time consuming operation to lift and hold all of the brushes 4 in the clear of the commutator while it is moved back into place.

In view of the above explanatory matter, it has been the object of this invention to provide a simple and effective tool that may be applied readily to a generator, and manipulated in a certain manner to cause all brushes to be engaged and simultaneously lifted, and thus retained out of the way, for the withdrawal of the commutator or for the replacement of the commutator and armature within the generator case or housing.

More specifically, the invention resides in a device of the character above stated, comprising for each brush of the generator, a pair of brush lifthooks, and means whereby all of these hooks may be actuated to engage and lift the brushes and to hold them in lifted position until reassembly of the generator parts has been completed.

Still further objects of the invention reside in the details of construction of parts in their combination, and in the mode of application and use of the device as will hereinafter be fully described.

In accomplishing the above mentioned, and other objects of the invention, I have provided the improved details of construction, the preferred forms of which are illustrated in the accompanying drawings, wherein:

Fig. l is a perspective view of a brush lifting device of the present invention, and illustrating its mode of application to a generator housing for lifting the commutator brushes.

Fig. la. is a detail showing the different positions of one of the brush lifting arms.

Fig. 2 is an end view of the brush lifting device; a part thereof being broken away for better showing of the action of brush engaging hooks.

Fig. 3 is a side view of the device as applied to a generator; parts being broken away and parts being in section, to better illustrate the details of construction, and a better understanding of use.

Fig. 4 is a detail, illustrating a mounting means for a pair of brush lifting hooks.

Fig. 5 is an end view of one of the guide members of the device.

Referring more in detail to the drawings:

In Figs. 1 and 2, Ill designates what may be a part of the housing or casing of a generator of the type with which the present device is to be used; this casing being of cylindrical form, and closed at one end, by a Wall l2 as shown best in Fig. 3. The wall I2 is formed with a central projecting hearing I 3, in which the mounting and driving shaft [4 of the armature i5 is rotatably contained. The armature is shown in part only and at its end carries the commutator, including the commutator bars designated by numeral I6.

It is to be understood that the details of construction of the generator are of no particular importance to this application except in so far as they concern parts of the present apparatus. Therefore, in the present illustrations, I have not shown parts not concerned with the invention and in Fig. 3 have rather generally illustrated the brushes that engage with the commutator and their supporting means. The brushes are shown to be in the form of rectangular blocks l8. In the usual makes of generators, there are four of these brushes and they are spaced at equal angular intervals about the commutator axis; each is mounted in a supporting guide member 2t, for movement directly toward and away from the commutator. In the present instance, the guides for the brushes are in the form of open, rectangular frames or collars in which the blocks l8 are contained, and these guides are rigidly 3 fixed to the end wall l2 by a rivet or other suitable means.

When the parts of the generator are assembled in operating relationship, the armature assumes a position in the housing ID in which it is shown in Fig. 3 and the several brushes will be engaged with the commutator and each is pressed into frictional contact therewith by means of a spring such as that designated at 25 in Fig. l. I

Formed in the housing II], at the locations of the four brushes, are openings 26 of substantial dimensions, as seen in Fig. 1, that give access to the brushes and make possible the use of the present device.

The device embodied by the present invention is designed to be applied directly to the end of the generator as illustrated in Fig. 3. In its present preferred form of construction, is comprises a disc-like plate 30, of slightly greater diameter than the casing Ill and formed with a cylindrical hub portion 3'1 at its center. The hub portion is open at its ends and is of such diameter that it may receive the bearing 13 therein.

Applied flatly against the outer face of the disc till, is an outer disk 40, and this also has a cylindrical hub portion 4'1 fitted to and rotatable on the hub portion 31 of disc 30. This latter hub serves as a handle for rotating the disc ill.

The inner disc 30 is equipped at intervals of 90, spacing, with radially extended arms 42 each of which forms a rigid guide member about which a collar 45 is mounted for inward and outward travel. Fixed to the opposite sides of each collar by a rivet or screw I1, is a pair of spring wire hooks or fingers 48, which extend inwardly toward the axial line of the device as best shown in Figs. 2 and 3. Fixed to the collars 45 and extending inwardly therefrom, and overlying the disc M are bars 50, each of which has a stud or pin 5| fixed in its inner end, that extends into a cam slot 52 in the disc 40.

It is shown in Fig. 2 that the "four cam slots 52 are all similarly located relative to the axis of rotation, each extending at the same angle and to the same extent so that upon rotation of the outer disc 40 upon the inner disc, all of the hook mounting collars 45, will be shifted simultaneously inwardly or outwardly on their respective guide arms to the same extent and all brush lifting hooks will be moved inwardly or outwardly together.

As was previously stated, the brush lifting hooks 4'3 are formed of resilient spring wire. Each has an 'inturned point 8 at its inner end and each arm is formed near its attaching end with a bend as at fill, forming a cam surface designed to ride on the adjacent side surface of the guide arm 42 as the arm mounting collars are shifted outwardly on the guide arms and thus for a greater part of the travel, to hold the hooked ends 58 of the hooks at opposite sides of the arm spring apart as indicated by the full line position of the hook in Fig. 1a. However, when the hooks are shifted toward their inner limits of travel, these cam surfaces disengage the side surfaces of the guide arms, and the pointed ends of the hooks will spring toward each other as in the upper dotted line position of the hook in Fig. 1a, and then, upon the final downward travel, the hook ends will engage beneath the bottom edge of the corresponding brush. Then, upon a slight opposite turning of the disc 40, the hooks will lift the brushes free of the commutator but still will not be disengaged therefrom; this latter position of the lifted brush being indicated in Fig. 2.

The discs may then be locked against relative turning by tightening a thumb nut 65 against the disc ill; the nut being threaded onto the outer end portion of a bolt 66 that is anchored in the disc 30 and extended outwardly through an arouate slot 58 in disc ll] as noted in Fig. 2. The slot is curved about the axial center of the discs.

Before applying the device to a generator, the disc all is rotated on disc 39 to a position at which all collars 45 will be shifted to their outer positions on arms $2. This locates all the hooks at positions that they will clear the generator housing when the device is applied.

Then the device is applied by placing the disc 3f! flatly against the end wall 12 of the generator as in Fig. 3 with the hub 13 extended into and centered in hub portion 3| of disc 36. To hold the device in position and against turning, I have provided a plurality of sprin fingers "it fixed inside the hub to engage yieldingly with the bearing it as seen in Fig. 2.

After the device has thus been applied for use, the disc Ml is rotated by grasping its hub portion ll, in a clockwise direction with reference to the showing in Fig. 2, thus to shift all hook carrying frames 4'5 inwardly along their guide arms &2. As the hooks app-roach their inner limits of travel, the cam bends of the hooks disengage the arms 82 and the pointed ends of opposedly related hooks snap toward each other and against the brushes. Then with the final inward adjustment of the hooks, the pointed ends engage beneath the brushes. Then the disc 46] is given a slight reverse adjustment, and the hooks all shift outwardly, lifting the brushes clear of the commutator. The thumb nut 66 is then tightened to secure the brushes in this raised position. The armature may then be withdrawn from the casing H] and replaced without any interference by the brushes. It is a simple matter to replace the armature, then to disengage all hooks and withdraw the device from the hub portion it.

Having thus described my invention, what I claim is new therein and desire to secure by Letters Patent is:

l. A brush lifting device for use in generator assembly and repair comprising a mounting plate adapted to be applied flatly against an end wall of a generator housing and having a hollow hub portion adapted to be holdingly applied to the end bearing of the said generator, arms extended radially from the edges of said plate in alignment with the location of the housing openings and brushes of the generator, a collar slideable along each of the said arms, a second plate rotatable about the hub portion of the first plate, and havmg cam slots formed therein at intervals corresponding to the spacings of the said arms and spirally inclined relative to the axis of rotation,

adjusting bars fixed to the said collars and equipped with means at their inner ends adapted to follow in the cam slots and whereby rotatable adjustment of the said second plate in opposite directions will effect the simultaneous inward and outward adjustment of the said collars, and hooks on said collars adapted, by the full inward adjustment of the collars, to be shifted into liftmg contact with the corresponding brushes of the generator and then by an initial outward adjustment of the collars, to lift the brushes clear of the generators commutator.

2. A device as in claim 1 wherein said hooks have camming surfaces adapted to engage with the arms on which their corresponding mounting collars are slideable to cause the disengagement of the hooks from the brushes when shifted outwardly beyond the said initial movement.

3. A brush lifting device for use in generator assembly and repair comprising a mounting plate adapted to be applied flatly against an end wall of a generator housing and having a hollow hub portion adapted to be holdingly applied to the end bearing of the said generator, arms extended radially from the edges of said plate in alignment with the location of the housing openings and brushes of the generator, a collar slideable along each of the said arms, a second plate rotatable about the hub portion of the first plate, and having cam slots formed therein at intervals corresponding to the spacings of the said arms and spirally inclined relative to the axis of rotation, adjusting bars fixed to the said collars and equipped with means at their inner ends adapted to follow in the cam slots and whereby rotatable adjustment of the second plate in opposite directions will effect the simultaneous inward and outward adjustment of the said collars, a pair of spring metal hooks attached to each collar and extended inwardly from the collar, and having camming surfaces thereon adapted to engage with the arm along which the collar is adjustable to cause the hooks to be held yieldingly in an opened apart relationship while being shifted into the generator housing through its openings to clear the opposite sides of the brushes, said camming surfaces being adapted to disengage the arms when the collars move through their final intervals of travel thus to allow paired hooks to spring toward each other to position to holdingly engage with the brushes, for lifting them incident to an initial interval of outward shifting of the collars.

4. A device as in claim 3 including releasable means for locking the plates against relative turning at any set positions of adjustment.

5. A brush lifting device for use in assembly and repair of generators, of that kind comprising a. housing having a cylindrical wall formed with openings and having brushes within the housing aligned with the openings and movable in directions radially of the housing; said device comprising a mounting member adapted to be fixedly applied to the end of the said housing and having arms extending radially therefrom beyond the housing in alignment with the position of the housing openings, hook mounting means movable along said arms, means on said mounting member and operable to effect the moving of said hook mounting means inwardly and outwardly along said arms, hooks on said hook mounting means adapted to be moved thereby into and from the housing through its openings, said hooks having camming contact with the arms along which they move to control their movement int and from liftin contact with the brushes,

6. A brush lifting device for use in assembly and repair of generators, of that kind comprising a housing having a cylindrical wall formed with openings and movable in directions radially of the housing; said device comprising a mounting plate adapted to be fixedly applied to the end of the said housing and having arms extending radially therefrom beyond the housing in alignment with the position of the housing openings, hook mounting means movable along said arms, means mounted on said plate and operable to effect the moving of said hook mounting means inwardly and outwardly along said arms, yieldable spring wire hooks fixed on said hook mounting means and adapted to be moved into and from the generator housing through its openings and having camming contact with the arms along which they move and by said caniming action to be caused to engage in lifting contact with the generator brushes during an initial interval of the outward shifting of the hooks and then to be disengaged therefrom when moved beyond the initial interval.

JOSEPH A. JOHNSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,251,835 Strutt l. Jan. 1, 1918 1,519,304 Hague Dec, 16, 1924 2,349,867 Heintz May 30, 1944 

